Getting (401) UnAuthorized error on some requests not all, but most - authentication

Question

I don't think this is a code issue, but we have a list of hundreds of addresses to process. Some return data and we are able to get Long and Lat but most return (401) UnAuthorized errors. What would cause this to happen? We have tried passing Host Headers and everything else, the REST API seems to work better in our development environment but throws way more errors when deployed to our Job Server. Any help on this issue will be greatly appreciated. We would like to understand why some calls work and others don't, we pass the same apiKey each time so this is really confusing. Thanks
Here is a code snippet using c# (Work in progress):
//GET THE LATITUDE AND LONGITUDE BASED OFF THE PHYSICAL ADDRESS
String clientAddress = clientRow["home_address"].ToString() + ", " + clientRow["home_city"].ToString() + ", " + clientRow["home_state"].ToString() + ", " + clientRow["home_zip"].ToString();
Logger.Debug("CLIENT ADDRESS: {0}", clientAddress);
String geocoderUri = "https://geocode.search.hereapi.com/v1/geocode?q=" + clientAddress + "&apiKey=xxxxxxxxxxxxxxxxxxxxx"; //KEY REMOVED FOR POSTING ON STACK OVERFLOW
var syncClient = new WebClient();
var content = syncClient.DownloadString(geocoderUri);
//CREATE THE JSON SERIALIZER AND PARSE OUR RESPONSE
DataContractJsonSerializer serializer = new DataContractJsonSerializer(typeof(AddressData));
using (var ms = new MemoryStream(Encoding.Unicode.GetBytes(content)))
{
var addressData = (AddressData)serializer.ReadObject(ms);
if (addressData.items.Count() > 0)
{
//INSERT THE LATITUDE AND LONGITUDE IN DB
String sLat = addressData.items[0].position.lat.ToString();
String sLong = addressData.items[0].position.lng.ToString();
Logger.Debug("CLIENT GEOLOCATION - Longitude: {0} Latitude: {1}", sLong, sLat);
insertLatLong(sLat, sLong, clientRow["clientID"].ToString(), 1);
}
}

Answer 1

Would you please try to use RestSharp lib for rest api?
Please see below sample code.
var client = new RestClient("https://geocode.search.hereapi.com/v1/geocode?q="+ clientAddress);
client.Timeout = -1;
var request = new RestRequest(Method.GET);
request.AddHeader("Authorization", "Bearer YOUR TOKEN");
IRestResponse response = client.Execute(request);
Console.WriteLine(response.Content);